Morgan, who began working at the firm’s New York office in 2004 after roles at Nike Communications and Mirimax, previously held the title of senior vice president and ran the firm’s recent L.A. expansion. Lylis, a veteran of Solomon McCown & Company who has spent the past ten years with SS, “played a large role” in the 2013 opening of SS’s Washington, D.C. wing.

Official statements after the jump.

In the release, Sachs and Sunshine write:

“Heather and Keleigh have long been our partners in that mission, and today we formalize that relationship…We couldn’t be prouder to formally welcome core members of our extended family—and two extraordinarily talented executives—as our new partners.”

The joint statement from Lylis and Morgan:

“When we joined the firm over a decade ago, we were a boutique company of ten providing media relations services.

It has been an incredibly exciting time for us to grow with the company. We are so thankful to Ken, Shawn and the entire company for giving us this opportunity and are excited for what’s to come.”